It was released on October 8, 2004, in conjunction with the album, and was written and produced by Park Jin-young with additional arrangement credits by Kwon Tae-eun.

In an attempt to attract a larger international audience, he changed his name from Bi (meaning 'rain' in Korean) to its English form, Rain.

Its video was played periodically on MTV (USA) to promote Rain’s first ever US concert, Rainy Day, in Madison Square Garden.

"[5] In 2014, music webzine Music Y ranked "It's Raining" number 31 in their list of 120 greatest dance tracks of all-time, writing that "From the breath-taking intro and heart pulsating sound to the bass beats, ...「It's Raining」has been successful in implanting its charisma into the rhythmic composition itself, and has been praised by DJs of the time as a world-class club tune.

Rain performed the song for the first time at the album's showcase event on October 8, 2004 at the Dome Art Hall at Children's Grand Park in Neung-dong, Seoul.

[14] On February 3, 2005, Rain made a performance with the song at the MTV Asia Aid 2005 in Bangkok, where he won the award for favorite Korean artist.